The optical information retrieved by Digital Holography Microscopy (DHM) consists of the quantitative values of phase and amplitude of the wave front reflected or transmitted by a sample. The phase change can be interpreted in particular as 3D topography. Moreover, in cell imaging it has been demonstrated that Quantitative Phase Measurement (QPM) enables to monitor changes of morphology, of intracellular concentration, channel activity and many others underlying cellular processes. It is a growing research field.
DHM is a technique which grabs the optical information, reflected or transmitted by the sample, in the form of a unique hologram. For creating a hologram, it is mandatory to combine two beams.
Commonly, those two beams are (1) the object beam containing the sample information, and (2) a reference beam, which should be as close as possible to a perfect uniform beam (plane wave or Gaussian beam). The reference beam also needs to be spatially and temporally coherent with the object beam. Otherwise, they would not interfere and not build up a hologram. A coherent monochromatic source such as a laser is typically used and is split into an object beam and a reference beam where the object beam passes through a sample and is combined with the reference beam to create a hologram that is recorded.
However, existing digital holographic microscopes are cumbersome and voluminous. Such devices are difficult to displace between laboratories and also unsuitable for fieldwork. The lack of portability also makes such devices unsuitable for educational purposes.
The present invention provides a solution to the above problems.
It is therefore a goal of the present invention to provide a portable holographic device or system which is mountable on any standard microscope and which is able to generate the same quantitative phase information as that of DHM, with reduced artifacts compared to known holographic devices.